Semantic Sensor Web is a new trend of research integrating Semantic Web technologies with sensor networks. It uses Semantic Web standards to describe both the data produced by the sensors, but also the sensors and their networks, which enables interoperability of sensor networks, and provides a way to formally analyze and reason about these networks. Since sensors produce data at a very high rate, they require solutions to reason efficiently about what complex events occur based on the data captured. Nevertheless, besides detecting complex events, sensor based applications also need to execute actions in response to these events, and in some cases, to execute these actions in a transactional way. In this paper we propose TRev as a solution to combine the detection of complex events with the execution of transactions for these domains. TRev is an abstract logic to model and execute reactive transactions. The logic is parametric on a pair of oracles defining the basic primitives of the domain, which makes it suitable for a wide range of applications. In this paper we provide oracle instantiations combining RDF/OWL and relational database semantics for TRev Afterwards, based on these oracles, we illustrate how TRev can be useful for these domains.